Question

The probability of guessing correctly at least 8 out of 10 answers on a true-false type examination is Select the correct answer from above options

Answer 1

In the examination , we have only two option True and False. So, The probability of getting True is , p= 1/2 And, similarly, probability of getting False is, q=1/2 The total number of Answer in examination , n=10 The probability of guessing correctly at least 8 it means r=8,9,10 We know, probability distribution P(X=r)=nCr (p)r qn-r P(X=r)=P(r=8)+P(r=9)+P(r=10)